1. Field of the Invention
The present invention relates to a parameter adjustment method, a semiconductor device manufacturing method, and a computer-readable recording medium.
2. Related Background Art
In recent years, semiconductor manufacturing technology has made a remarkable progress, and semiconductors with a minimum processing size of 90 nm have been mass-produced. Such a microfabrication has been achieved by an astonishing progress in fine patterning technology such as mask process technology, lithography process technology, and etching process technology. In order to follow the recent sharp drop in market price, it is needed to lower costs quickly, and it is very important to use a technique for mass-producing products early and stably.
In order to achieve mass-production, stable manufacturing is required by a plurality of manufacturing devices. However, when a process margin is reduced with a progress in microfabrication, a problem occurs in that the difference in performance variation between manufacturing devices affects yield. In order to maintain stable and high yield, it is important to minimize the difference in performance between a chip manufactured by a manufacturing device serving as a reference and a chip manufactured by another manufacturing device. The above problem will be described in detail with reference to an exposure device.
For example, if a problem occurs in a different exposure device, it is conventionally difficult to provide a guideline on how to set parameters and their adjusted values for the exposure device. The difficulty lies in the following circumstances:    1) The exposure device has a limited number of adjustable parameters affecting size variation on a wafer (light shape and aberration only);    2) No fine parameter adjustment is required because the process margin is relatively large;    3) Relatively uniform distribution of diffracted light with respect to lens allows for a small size variation on a wafer due to an aberration control of a light and lens; and the like.
In view of the above, the parameters for the manufacturing device are optimized based on the experience of a technician to provide a stable manufacturing.
However, with the recent progress in microfabrication, the following circumstances are observed:    a) Minute changes in parameter of the exposure device that are not conventionally considered (e.g., degree of polarization of an exposure light, flare, NA (numerical aperture), synchronization accuracy of the exposure device, and the like) are beginning to affect the finished shape on a wafer;    b) Customized light shape is required to cope with the microfabrication, and thus the effect of minute variations of the light shape on the size on a wafer is increasing relatively;    c) When a specific fine pattern is formed using the above light b), the diffracted light passing through the lens is focused on a specific position. As a result, the effect of the lens performance at a specific position (aberration and light transmission of the lens) on the size on a wafer is increasing relatively.
Under such circumstances, the specification of each exposure device parameter needs to be tightened. However, it is very difficult to satisfy every specification. Accordingly, what is required is a technique for quantitatively estimating the effect of a variation of an exposure device parameter on a finished shape on a wafer to perform a proper and rigorous adjustment on a large number of exposure device parameters.